1. Field of the Invention
The present invention relates to an electron emitting element for emitting electrons by application of a voltage and a method for producing the same.
2. Description of the Related Art
Conventionally, MIM (Metal Insulator Metal) type and MIS (Metal Insulator Semiconductor) type electron emitting elements have been known. These electron emitting elements are surface-emission-type electron emitting elements, each of which accelerate electrons by utilizing quantum size effect and an intense electric field in the element so that electrons are emitted from a flat surface of the element. These electron emitting elements do not require an intense electric field outside the elements, because the electrons accelerated in an electron acceleration layer in the elements are emitted to the outside. The MIM type and MIS type electron emitting elements can therefore overcome a problem of breakdown of the element by sputtering due to ionization of gas molecules and a problem of ozone generation, which are likely in the Spindt type, CNT (carbon nanotube) type and BN (boron nitride) type electron emitting elements.
In addition, there has been developed an electron emitting element that is capable of stable electron emission in the atmosphere and inhibited from generating harmful substances such as ozone and NOx when emitting electrons. For example, there has been known an electron emitting element including, between electrodes, an electron acceleration layer containing: conductive fine particles composed of an electrical conductor and having a potent antioxidative effect; and an insulating material having a size larger than the size of the conductive fine particles (for example, Japanese Unexamined Patent Publication No. 2009-146891).
However, the above-described electron emitting element has been desired to be improved in electric power consumption, because the current in the element tends to be increased as the amount of electrons being emitted from the element is increased.